Method for shredding portions of bituminous material into recyclable granules

Abstract

A machine for shredding portions of bituminous material in the solid-state into granules in the solid-state. The machine comprises a pressing member provided with a piston which is axially mobile inside a perforated tubular body along an axis and is provided on the head thereof with an internal concave portion having a shape substantially complementary to a projecting part present in an axial end of the perforated tubular body. On the head of the piston through-openings are made, which extend radially along a direction approximately transversal to the axis and are in communication with the internal space of the concave portion.

The invention claimed is: 
     
       1. A machine for shredding portions of bituminous material in the solid-state into granules in the solid-state, comprising:
 shredding means comprising a perforated tubular body, which extends along a first axis and has at an axial end a wall provided with a projecting part protruding towards the internal space of said perforated tubular body,
 pressing means provided with a piston which is axially mobile inside said perforated tubular body along said axis and is provided on the head with an internal concave portion having a shape complementary to said projecting part, 
 movement means adapted to displace said piston along said first axis towards said projecting part in order to axially compress said portions inside said perforated tubular body against said projecting part shaped so as to radially push said portions towards the through-holes present in said perforated tubular body so as to extrude the portions into filiform portions, and
 cutting means for cutting said filiform portions so as to shred them into granules, 
 
 
 said machine being characterised in that:
 on the head of said piston one or more through-openings are made, which extend radially along a direction transversal to said longitudinal axis and are in communication with the internal space of said concave portion. 
 
 
     
     
       2. The machine according to  claim 1 , wherein said piston has a substantially cylindrical shape; said through-openings form radial channels on the head of said piston, which are adapted to unload the portions compressed and accumulated in said concave portion towards the through-holes present in said tubular body so as to extrude them into said filiform portions. 
     
     
       3. The machine according to  claim 1 , wherein said through-openings of said head of the piston are sized so as to increase the radial compression exerted by said projecting part against said portions accumulated in said concave portion, in response to the longitudinal compression of said piston against said projecting part. 
     
     
       4. The machine according to  claim 1 , wherein said piston comprises a plurality of through-openings angularly spaced from one another about said axis. 
     
     
       5. The machine according to  claim 4 , wherein each through-opening of the said plurality of through-openings comprises:
 at least two internal walls which face one another and extend radially towards the axis; 
 wherein at least one of the at least two internal walls of each through-opening forms, with an internal wall of the at least two internal walls of an angularly adjacent through-opening of the plurality of through-openings, a partition edge which extends inside the concave portion and is shaped to cut into said portions during the axial compression thereof carried out by said piston against said projecting part. 
 
     
     
       6. The machine according to  claim 5 , wherein said partition edges have a triangular or wedge-shaped cross section orthogonal to the axis, wherein the tip of the partition edge faces towards the concave portion. 
     
     
       7. The machine according to  claim 1 , further comprising one or more longitudinal notches on the annular edge of the head of said piston, each of which extends parallel to the axis (A) from said edge until reaching a relative opening of the plurality of through-openings. 
     
     
       8. The machine according to  claim 7 , wherein said longitudinal notches are positioned on the head of the piston according to a distribution to traverse the corresponding openings of the plurality of openings in an angularly alternated manner. 
     
     
       9. The machine according to  claim 1 , wherein the annular edge of the head of the piston is shaped so as to have an annular recess along the inner side thereof facing the concave portion. 
     
     
       10. The machine according to  claim 9 , wherein said annular recess forms, along the inner side of the edge of the head of the piston, a discontinuous circular ring radially protruding towards said projecting part.